Hydrocarbon conversion



R. B. DAY ETAL HYDROCARBON CONVERSION Feb. s, 1944.

Filed Jan. 2l 1941 F /PC 770/1447 CA TAL V/c PEA/T0139 fw y, Z m/l m 7 Mw 22 M E A 8 5 W mi V p w IY .Iv I 5 f5 w /e/ 9 r 4 w d il, 1 ltl Y 1v PMAN |1 /4 79() M DMW 4 7 7 w m MM L 1+ 7 w GM 4 5 2 WT n@ f 11.. A| PMQE g E; .m4 0 a X p mm l5 4 f S of@ rz 7 7 W M w ,o E M 5 H W L 8 4.11.1iH E F -KTO 0 J a /s w www E Patented Feb. 8, `1944 a nrnnocanoNcoiwlmsron Roland B. Day and' Elmer R. Kanhofer, Chicago, lll.,assignors to Universal Oil Products Company, Chicago, Ill., acorporation of Delaware Application January 21, 1941, serial No.315,106- 'z claim.` (ci. 19o-sa) 'Il'his invention relates toimprovements in the method of effecting conversion of hydrocarbon voilin as combination catalytic and pyrolytic cracking system in whichrelatively high yields ,of high octane rating gasoline are produced.

More specically the invention relates to im provements in the method ofconducting the catalytic conversion' reaction and provides a moreaccurate means for controlling temperatures and space vvelocities in thecatalytic conversion treatment.

In the catalytic cracking of hydrocarbons to N produce lower boilingproducts therefrom, it has been found that insufllciently convertedhydrocarbons formed in the process contain relatively large quantitiesof cake forming hydrocarbons which are reduced tocoke ii returned to thecatalytic crackingv step with no intermediate treatment for theirremoval or conversionv into hydrocarbons more vsusceptible to catalyticcracking. I

. yIt is noi` considered advisable to treat such insufficientlyconverted hydrocarbons from tatalytic cracking to rempve the carbonforming. constituents contained therein by solvent extraction, forexample, but more generally by pyrolytic cracking. In the operationsinvolving the pyrolytic treatment of the insumciently convertedhydrocarbons from a catalytic cracking process wherein at least .j aportion` of the reaction products formed in the pyrolytic cracking stepis supplied to the catalytic cracking step, it has been shown that thedeposit of oarbonaceous substances on, the' catalyst is less in suchcases for the same quantity of oil converted than in a once-throughoperation on'a virgin stock.. In the latter type of operation, however.relatively large quantities of gasoline this gasoline will ordinarily befrom 1'0 to 15.

points lower in octane rating than that formed in the catalytic crackingstep with the result that the octane ratingv of the nal blend of the twodistillates formed in the two cracking steps is considerably below thatwhich may be obtained' when`recycling all of the insufncientlyconvertedhydrocarbons direct to the catalytic sirable feature of highcarbon deposition normally associated with such a process.

It has been found that the octane rating of improvement oi the octanerating of this material is probably due to an isomerizing effect, andalthough the conditions employed in the catalytic vcracking step are notoptimum for the isomerizing reaction,' improved results are definitelyshown. TheA relatively low liquid hourly space velocities employed inthecatalytic cracking step as compared to the higher space velocitiesdesirable in the isomerizing reaction will cause an 4increased gasproduction when gasoline' boiling range hydrocarbons are returned tothis step as compared to the gas production when the pyrolyticallyformed gasoline is separately treated.

In our invention. to obviate some 'of the undesirable featuresassociated with the processes previously mentioned, we provide acatalyst zone separate from the initial catalyst cracking zone to whichall of the conversion products from the catalytic cracking step plus thepyrolyticallyV formed gasoline is supplied whereby conditions in suchseparate zone may be controlled within the limits optimum for improvingthe octane 'rating of the pyrolytioally formed gasoline in the absenceof any substantial amount ot crack`' ing to lighter products and coke.Preferably also and in accordance with .the objects of the invention,the pyrolytically formed gasoline with or without the separation otlight normally gaseous hydrocarbons is separately heated and the heateddistillate thereafter commingled with the conversion products from thecatalytic cracking step, the heating of such distillate being controlledso that the temperature oi the final mixture is optimum for the reactionto be accomplished. Thevolume o'f such separate cata ,lyst zones may becontrolled within desirable limits so that the space velocities oi thehydroare formed in the pyrolytic cracking step and carbon reactantsbrought in contact with the lcatalyst contained therein are optimum -forthe process.

In one embodiment the invention comprises subjecting a readilyvaporizable hydrocarbon. oil

, to contact with a mass of cracking catalyst to cracking stepneglecting in such cases the nudel the gasoline produced in thepyrolytic crackingstep may be improved by commingling such' gasolinewith the stream of hydrocarbon oil to be converted in thecatalyticcracking step. The

eifect conversion into lower boiling products, commingling theconversion products with fractionated 'vapors separated as hereinafterset forth and passing the mixture in Contact with a separate mass ofcracking catalyst, fractionating thecomprise passing a readilyvaporizable hydrocarbon oil heated to a cracking temperature in contactwith a mass of cracking catalyst to effect conversion into lower boilingproducts, commingling the conversion products with fractionated vaporsseparated as hereinafter set forth and passing the resultant mixture incontact4 with a separate mass of cracking catalyst at a relativelyhigher space velocity thanthat employed in the rst mentioned mass,fractionatixr g, the resulting conversion products to separatefractionated vapors boiling substantially in the range of gasoline frominsufilciently converted hydrocarbons, cooling and condensing vsaidfractionated vapors, subjecting said insufliciently convertedhydrocarbons to pyrolytic conversion together with a diflcultlyvaporizable hydrocarbon oil, fractionating vaporous reaction productsformed in the pyrolytic cracking step to sep-` arate fractionated vaporsboiling substantially in the range of gasoline, a-lightreilux'condensate, and a heavier reflux condensate, subjecting the lastmentioned fractionated vapors to treatment in the manner hereinbeforeset forth, supplying 'said light reflux condensate to the catalyticcracking step and supplying said heavier reflux condensate to thepyrolytic cracking step.

Fig. 1 of the accompanying diagrammatic drawing illustrates inconventional side elevation one specific form of the apparatus to whichthe improvements set forth in this invention may be applied. Fig. 2illustrates a modified form of re7 `actorirom that shown in Fig. 1. Itis understood, of course, that the invention herein discrackingandvisdirected to-aprocess in w i a pyrolytically formed gasoline isproducedconcurrently with the production 4of-catalytically formedgasoline.

for the process, is introduced through line I containing valve 2 to pump3. Pump 3 discharges through line 4' containing valve 5 into heatingcoil 6. Preferably also, the relatively light oil in line I iscommingled withlight redux condensate separated in the manner to bedescribed' and, as previously inferred, such light reflux condensate mayin some cases comprise the sole charge to this step.' The oil in passingthrough heating coil 6 is vaporized and heated tc a cracking temperatureby means of heat supplied from furnace l. The cracking temperature towhich such oil is heated will in most cases fall within the range of 800to 1200 F. and. usually within the range of 900 to 1050 F. Heated vaporsleaving coil 6 vunder a pressure of from substantially atmospheric to200 pounds per square inch or thereabouts pass through line B and may be'introduced to either reactor B by way of valve '9 or to reactorI A byway of line lil containing valve il.

.The system illustrated in the accompanying drawing is shown asconsisting of two reactors A and B in which catalytic cracking isaccomplished and two communicating reactors A and B' in which eetruytictreatment of the pyrolytically formed gasoline and the catalyticconverswitching the stream lof hydrocarbon reactants readily understoodsince the cracking 'reaction isv ordinarily accompanied with thedeposition of carbonaceous substances which must lbe removed In theprocess illustrated in the accompanying drawing charging stock'may.comprise, for example, a relatively light readily' vaporizablehydrocarbon oil in which case such oil is introduced or supplied to thecatalytic cracking step or in some cases the charging oil may comprise arelatively Y heavy dimcmuy veporizome hydrocarbon on and in such casesit is supplied to the pyrolytic cracking step. In still other cases thecharge may I comprise a composite of relatively Jightand relativelyheavyoils and in such cases it is usually desirable to supply this'oilto the pyrolytic crack- 1 `meister either diremmo the heating con butmore generally to the fractionator receivingthe 'Y from the pyrolytic.vaporous reaction products cracking step.

Referring -now to the drawing, a relatively light readily vaporizablehydrocarbon oil, which in materials composited with one by periodfrequent regenerationv and thereby maintain the bed or beds of catalystin a highly active state. In the process. of the invention hereindescribed, it is 'intended that regeneration be accomplished by wellknown methods of which contain one or a plurality of beds of catalyticmaterial through whichthe hydrocarbon reactants pass either in series orparallel.

Catalysts which have-been found to be elketive in Athe catalyticcrackingof hydrocarbon vapors and in4 the treatment oi' pyrolytic'ally formedgasoline may comprise. for example, powder, pellets or granules'ofsynthetically prepared purified silica or other siliceous and refractoryor morel of the compounds Iselected from the group consisting ofalumina, zirconia, and thoria. In addition', the hydrosilicates ofalumina, acid treated clays. or the like, have also been found to beeifective in the. cracking treatment of vhydrocu'bon `vapors. Althoughthe catalysts above recited are generally considered to be the.preferred catalysts.

their use is not to be construed as alimiting. feature, for variousother catalysts well known to those in the art may be employed within,the

.some cases may comprise the sole charging stock '7l broadscope oftheinvention.

be'obtained when using the synthetically prepared catalyst, such asthose of the silica-alumina or silica-alumina-zircon-ia type, but it isnot intended that catalysts of the acid treated clay type be excludedfrom use in such process, for these catalysts will valso exert somebenecial Conversion products leaving either reactor A or B are directedthrough respective lines l2 and i3 containing respective valves I4 andI5 and are commingled with a heated pyrolytically.

formed distillate supplied in the manner to be .described followingWhichthe resulting mixture is intrduced to either one of the reactors A'or B depending, as in the above case, upon whether at such instance thereactor is employed in processing or the catalyst contained therein isundergoing regeneration. The invention contemplates switching streams ofhydrocarbons introduced to reactors A' and B' at the same instant thatthe stream of reactants .is switched between reactors A and B.4 Whilecatalytic conversion is being accomplished in reactor A the catalytictreatment is accomplished in reactor A and at the same time the/catalystcontained in reactors B -and B is undergoing regeneration. It follows ascompared with those employed in reactors A and B, for whereas spacevelocities of the order of l.5 to 1 0. are employed in reactors A- andB, space velocities of the order of to 20 are employed in reactors A!and B'. Reaction temperatures within reactors A' and B' are preferablyvl of the order of 800 to 1200 F., but it is more reactor B' are directedthrough line Il containing valve I3 into line Il. In any event,conversion products in line i3 vare supplied to fractionator 2li.Fractionator 23 together with'the condensing and collecting equipment incommunication therewith is preferably operated at a pressure ofsubstantially the same order as that employed on the outlet of reactorsA' and B'. Cbnversion products supplied to fractonator 2l arefractionated therein to separate fractionated vapors preferablycomprising a full boiling range gasoline. such as, for. example. onehaving a 400 F; end point from in'suillciently converted hydrocarbonsand the latter condensed within the' fractionator and removed as aliquid from the lower portion thereof in the manner to be described. I l

Fractionated vapors separated in fractonator 20 are conducted throughline 2lv containing valve 22 to cooling and condensation in condenser23. Distillate together with undissolved and uncondensed gases leavingcondenser 23 is directed through line 24 containing valve 2,5 intoreceiver 26 wherein the distillate and gases are collected 'andseparated. Undissolved and uncondensed gases collected and separated inreceiver 26 are removed therefrom by way of line 21 .containing valve278 and recovered as a product of the process. A portion of thedistillate separated in receiver -26 may be returned to the upperportion of fractonator 20 by well known means, not shown, as a refiuxingand cooling medium in controlling the end point of the fractionatedvapors and the residual portionthereof removed general practice toemploy temperatures below 1000 F. The invention also contemplates sub--stituting a single reactor for the double reactor,

such as A and A'. Fig. 2 illustrates this modi'ed form of reactor. Inthis figure appurtenances which are the same as those shown in Fig. 1haya received the same legends. Thus, when processfing reactor AA',heated vapors in line 3 are directed through line Il) and valve ii intoone end of the reactor .and pass in contact with a body of catalystmaintained therein. Conversion products are withdrawn from the oppositeend of reactor-AA through line I6 andvalve I1 for further treatmentaswill be described in connection with Fig. 1. Heated pyrolyticallycracked distillate is introduced into reactor AA at an Aintermediatepoint and passes with the heated vapors -through the remaining portionof the reactor. Thus the pyrolytically formed distillate to be treatedin the manner above described may be introduced to the singlereactor atsome intermediatepoint so that the time in which these hydrocarbonsremain in contact with the catalyst is not in excess of the timerequired to eiect the desired improvement in octanerating.

With reactors A and A' on process conversion products leaving reactor A'are directed through from receiver 26 by way of line 23 containing'valve 30 and recovered as a product of the process or subjected to anydesired further treatment.

Insufiiciently converted hydrocarbons separated in fractonator 20 varedirected through line v3l containing valve 32 yto pump 33 whichdischarges through line 34 containingvalve 35 into heating coil 36.. Insome operations, also, heavy reflux condensate and/or a relativelyheavyv oil contain-` ing diilicultly vaporizable hydrocarbons may becommingled with the insuilicintly converted hydrocarbons in line 34 inthe manner to be described and the total mixture introduced -to heating.coil 36. The oil supplied to coil 36 in passing therethrough is heatedto a crackingtemperature of the order 0f 850 to 1000 F., or thereabouts,by means of heat supplied from furnace 3l.v The heated oil leaving coil36 is directed through line 38 containing valve 39 and intro-4 ducedinto reaction chamber 40 which is preferably operated under asuperatmospheric pressure of the order of 100 to 500 pounds per squareinch and wherein cracking instigated in the heating coil is allowed toproceed to a greater degree of completion.

Reaction products leaving chamber 40 are directed through line 4Icontaining valve 42 into vaporizing and separating chamber 43 which is Ypreferably operated at a reduced pressure relative to that employed inchamber 40 and the pressure maintained therein will usually fall withinthe range of 50'to 200 pounds per square inch. Vaporous reactionproducts are separated from non-vaporous reaction products invchamber 43line I6 containing valve i, and with reactors B and B' on processconversion products leaving and the latter substantially furthervaporized to form a non-vaporous liquid residue which is recovered as aproduct of the process by way of line 44 containing valve 45. Vaporousreaction products together with vaporsv evolved within chamber 43 aredirected through line 46 containing valve 41 into fractonator 48 andthis fractionator may be operated at a pressure of Asubstantially thesame order as that employed on the outlet of chamber 43. The vaporousreaction products are fractionated within fractionator 48 to separatethe fractionated vapors from higher boiling hydrocarbons, containing insome instances only low boiling products, such as,for

example, hydrocarbons having 5 carbon atoms and less to the molecule.Generally, however, this fraction will include hydrocarbons boilingwithin the range of gasoline. The higher boiling hydrocarbons separatedvin fractionator 48 are A condensed therein as reilux condensate and mayat times be collected as a total reflux condensate while at other timesfurther separation may be accomplished in fractionator 48 to separate a.light reiiux condensate from the heavier reflux condensate. Y

Fractionated vapors separated in fractionator 48 vare conducted throughline 49 and may be directed through valve 50 to cooling and condensationin condenser 5I. VDistillate together with undissolved anduncondensedgases from condenser 5I is directed through line 54 containing valve tocollection and separation in receiver 5B. Undissolved and luncondensedgases collected and separated in receiver 55 are removedtherefrom by wayof line 51 containing valve 58 and recovered as a. product of theprocess.

In an operation involving the removal of only low yend pointfractionated vapors from fractionator 48, such as hydrocarbons having 5carbon atoms and less to the molecule, the distillate collectedinreceiver 56 in such instance is removed therefrom by way of line 59containing valve 60 and recovered as a product of the process. In anoperation involving the removal of fractionated vapors from fractionator48 over the full boiling range of gasoline, the distillate in excess ofthat required in refluxing and cooling the upper portion of-fractionator 48 is directed through line 6| containing valve |52 topump 63. Pump 63 ischarges through line 64 containing valve 65 'i toheating coil 66. In `Qns latter type operation provisions are also madefor by-passlng the cooling andcondensing step, in which case thefractionated A vapors in line 49 are conducted through line 52containing valve 53 into line 64 by means of which they are supplied tocoil 66.

Fractionated vapors supplied to coil 56, either as a liquid or vapor,are heated therein to a temverted hydrocarbons from fractionator 2l fortreatment in the manner described. vLight rcflux condensate in suchveases is conducted through line containing valve 8l to pump 82 whichdischarges through line 83 containing valve 84 into line 4 wherein suchlight reflux condensate commingles with the relatively light hydrocarbonoil and is subjected to conversion in commingled state therewith in themanner previously described.

A11 of the methods of operation described above ,relate to -a process inwhich the charging stock 4diflcultly vaporizable hydrocarbon oil or thecomposite charge is supplied through line 85 containing valve 86 topump81. Pump 81 discharges through line 88 and the oil in line 88 may bedirected through valve 89 into fractionator 4l wherein it undergoesfractionation in commingled state with the reaction products supplied-to fractionator 48 in the manner previously 'de'- scribed, or thehydrocarbon oil in line II may be directed through line 90 containingvalve Il into line 16, commingling thereinv with reflux condensate inline 1li after which it is subjected to treatmentin the mannerpreviously described.

Fromv the foregoing it is quite obvious that there are many-types ofoperation in which the improved form of this invention is useful, and itis my intention, therefore, not to limit the invention to any of thespecific types of operation peratureof the order of 800 to 1100 F. bymeans of heat supplied from furnace 61. Heated vapors leaving coil 66are directed through line 68 containing valve 68 into line 10 followingwhich such heated vapors are directed either through valve 1| into line,I2. or valve 12 into line 'I3 for treat-l ment in the' manner previouslydescribed.

The total reflux condensate separated in frac- I tionator 48 isconducted through line 13 contain-- ing valve -14 to pump 15. Pump 15discharges through lines 16 and 11 and valve 18 into line 83 by 4meansof which such reflux condensate is supplied tc line- 4, commingling withthe relatively light oil for treatment in the mannerpreviouslydescribed. I p

In an operation involving both the separation fof light and heavy refluxcondensate the two condensate fractions are separately removed fromfractionator 48 and subjected to treatment in the manner to bedescribed. Heavy reflux eenden-v sate in such cases is conducted throughline 13A containing valve 14 to pump-.15 which discharges through line'I6 containing valve 19 into line I4, "ommingliug therein with theinsumciently conherein disclosed but rather to apply it generally 'toall types of operation in which a pyrolytically formed gasoline isproduced kwhich may show improvements in octane rating' by catalytictreatment of the type herein described.

An example of one specific operation of the process as it may beaccomplished in an apparatus such as illustrated and above described isapproximately as follows: The chargingoi'l, a 33' A. P. I. gravityMid-Continent gas oil, is heated to a temperature of about 950 F.'Thejresulting heated vapors under a pressure of about 30 7 pounds perlsquaiefinch are passed in contact 'with a mass of silica-aluminacatalyst of the type previously mentioned at a liquid hourly spaceveloeity of 4.

Conversion products leaving the mass of cracking catalyst are eommingledwith a gasoline distillate separated in the manner to be described andthe resulting mixture passed in contact. with a second,mass of crackingcatalyst at a liquid hourly space velocity of 15. Conversion productsleaving the last mentioned mass of cracking catalyst is fractionated toseparate fractionated vapors of the gasolineboiling range from thehigher boiling insuiiciently converted hydrocarbons and the formersubjected to coolingY and condensation and recovered as a product of theprocess.

Insumciently rated in the manner described are eomniingicd convertedhydrocarbons 1 sepa.-V

with a heavy reflux condensate the mixture subjected to. pyrolyticconversion in a. heating coil and communicating reaction chamber at atemperature of about 920 F. and a superatmospheric pressure of 200pounds per squareinch at the outlet of said reaction chamber. ReactionIproducts leaving said reaction chamber are supplied to a vaporizing andseparating chamber 'wherein Vaporous reaction products are substantiallyseparated from non-Vaporous liquid residue andthe latter recovered as aproduct of the process.

Vaporous reaction products separated in the manner described arefractionated to separate fractionated vapors of about the gasolineboiling range,l light reflux condensate having an end boiling point notsubstantially in excess of 650" F., and heavy rei-lux condensate. 'Iheheavy reflux condensate is supplied to the pyrolytic cracking step andthe light reflux condensate to the catalytic cracking step. Thefractionated vapors are separately` heated to a temperature of 950 F.and the heated vapors thereafter commingled with the conversion productsfrom the first catalytic cracking zone and the resulting mixturesupplied to a second catalytic cracking zone in the manner previouslydescribed.

From an operation employing conditions as above described one may obtainapproximately 72% of 76 octane rating gasoline, approximately 11% ofnon-Vaporous liquid residue, the balance being principally carbon, gas,and loss.

We claim as our invention:

1. In a process for the conversion of hydrocarbon oil wherein relativelylight readily vaporizable hydrocarbons are vaporized and heated to acracking temperature and Asubjected to catalytic conversion in a zonecontaining catalyst capable of effecting the desired cracking reaction,and relatively heavy difc'ulty vaporizable hydrocarbons are subjected topyrolytic cracking, insum-A ciently converted hydrocarbons from thecatagasoline are supplied to the pyrolytic cracking step, the methodwhich comprises commingling gasoline from the pyrolytic cracking stepwith the conversion products from the catalytic cracking step, andsubjecting the resultant mixture to treatment in a catalyst zoneseparate from the catalytic cracking zone at a liquid hourly spacevelocity higher than that maintained in said catalytic cracking step toimprove the octane rating of such gasoline. t

2. The improved process of claim 1 further characterized in that thegasoline supplied to the ciently converted hydrocarbons from thepyrolytic cracking step to the said catalytic cracking zone, heatingfractionated vapors formed in the pyrolytic cracking step to aconversion' temperature, and commingling such heated vapors with theconversion products from said catalytic conversion step and subjectingthe mixture to treatment in a catalyst zone separate from the catalyticcracking zone at a liquid hourly space velocity higher than thatmaintained in said catalytic cracking zone to improve the octane ratingof the heated vapors.

4. A process for the conversion of hydrocarbon oil which comprisesmaintaining a catalytic cracking zone and a pyrolytic cracking zone,separately fractionating conversion products from both Y cracking zonestoseparateiractionated vapors, including hydrocarbons boiling within therange of gasoline from higher boiling insufdciently convertedhydrocarbons, supplying higher boiling insufficiently convertedhydrocarbons from the catalytic cracking step to the pyrolytic crackingstep, further separating the higher boiling insuilllytic cracking step,including those boiling above y ciently converted hydrocarbons from thepyrolytic cracking step into light and heavy reflux condensates,supplying said heavy reux condensate to the pyrolytic cracking step,supplying the light reflux condensate to the catalytic cracking step,heating the fractionated vapors from the pyrolytic cracking step, andcommingling such heated vapors with the conversion products from saidcatalytic cracking step and subjecting the mixture to treatment in acatalyst zone separate from the catalytic cracking zone at a liquidhourly space. velocity higher than that maintained in said catalyticcracking zone to improve the octane rating of the heated vapors.

5. In a process for the conversion of hydrocarbon oil wherein relativelylight readily vaporizable hydrocarbons are vaporized and heated to acracking temperature andsubjected to catalytic conversion in a zonecontaining catalyst capable of effecting the desired cracking reaction,and relatively heavy diiculty vaporizable hydrocarbons are subjected topyrolytic cracking. insuiliciently converted hydrocarbons from thecatalytic cracking step, including those boiling above gasoline aresupplied to the pyrolytic cracking step, the method which comprisesintroducing gasoline from the pyrolytic cracking step tothe catalyticcracking zone at some selected intermediate point S0 that Such gasolineDRSSES in 00nversion step; l

tact with the catalyst in said catalytic cracking zone at a relativelyhigher liquid hourlyspace velocity than the total reactants supplied tosuch zone. y

6.7A hydrocarbon conversion process which comprises pyrolyticallycracking a relatively heavy 'oil to form thermally cracked gasoline,simultaneously subjecting a lighter oil to catalytic conversion incontact with a cracking catalyst, commingling at least a portion of saidgasoline with the resultant catalytic conversion products, andsubjecting the resultant mixture at conversion temperature to contactwith cracking catalyst at a liquid hourly space velocity higher thanthat maintained in the first-mentioned catalytic con- 7. A conversionprocess which comprises catalytically cracking hydrocarbon oil,commingling thermally cracked gasoline with the resultant catalyticconversion products, and subjecting the resultant mixture at conversiontemperature to contact with cracking catalyst at a liquid hourly spacevelocity higher than that maintained in the first-mentioned catalyticconversion step.

ROLAND B. DAY. ELMER R. KANHOFER.

